The mole fraction of ethylene glycol (C₂H₆O₂) in a solution containing 20% of C₂H₆O₂ by mass is:

1. 0.932
2. 0.0672
3. 0.832
4. 0.732

The molarity of a solution containing 5 g of NaOH in 450 mL solution is:

1. 0.188 mol dm^–3

2. 0.478 mol dm^–3

3. 0.378 mol dm^–3

4. 0.278 mol dm^–3

The molality of 2.5 g of ethanoic acid (CH₃COOH) in 75 g of benzene is:

1. 0.656 mol kg^–1

2. 0.616 mol kg^–1

3. 0.556 mol kg^–1

4. 0.456 mol kg^–1

If N₂ gas is bubbled through water at 293 K, how many millimoles of N₂ gas would dissolve in 1 litre of water?
(Partial pressure of nitrogen = 0.987 bar, Henry’s law constant for N₂ at 293 K = 76.48 kbar).

1. 0.716 mmol

2. 0.616 mmol

3. 0.726 mmol

4. 0.516 mmol

The vapour pressure of pure benzene at a certain temperature is 0.850 bar. A non-volatile, non-electrolyte solid weighing 0.5 g is added to 39.0 g of benzene (molar mass 78 g mol^–1). Vapour pressure of the solution, then, is 0.845 bar. The molar mass of the solid substance is:

18 g of glucose, C₆H₁₂O₆, is dissolved in 1 kg of water in a saucepan. The temperature at which water boil at 1.013 bar is-

(K_b for water is 0.52 K kg mol^-1)

1. 383.202 K

2. 373.202 K

3. 363.202 K

4. 393.202 K

The boiling point of benzene is 353.23 K. When 1.80 g of a non-volatile solute was dissolved in 90 g of benzene, the boiling point is raised to 354.11 K. The molar mass of the solute is:

K_b for benzene is 2.53 K kg mol^–1

1. 55 g mol^–1
2. 64 g mol^–1
3. 58 g mol^–1  
4. 68 g mol^–1

45 g of ethylene glycol (C₂H₆O₂) is mixed with 600 g of water. The freezing point of the solution is:

1. 268.15 K
2. 270.95 K
3. 272.75 K
4. 267.15 K

1.00 g of a non-electrolyte solute dissolved in 50 g of benzene lowered the freezing point of benzene by 0.40 K. The freezing point depression constant of benzene is 5.12 K kg mol^–1. The molar mass of the solute is:

200 cm³ of an aqueous solution of a protein contains 1.26 g of the protein. The osmotic pressure of such a solution at 300 K is found to be 2.57 × 10^–3 bar.  The molar mass of the protein is: